package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlogLike(blog);
        });
        // 查询用户
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("笔记不存在");
        }
        queryBlogUser(blog);
        isBlogLike(blog);
        return Result.ok(blog);
    }

    public void isBlogLike(Blog blog) {
        UserDTO user = UserHolder.getUser();
        if (user==null){
            return;
        }

        //从redis中获取数据判断用户是否点赞
        Long userId = UserHolder.getUser().getId();
        String key = BLOG_LIKED_KEY + blog.getId();
        Double member = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(member!=null);
    }

    @Override
    public Result likeBlog(Long id) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();

        //从redis中获取数据判断用户是否点赞
        String key = BLOG_LIKED_KEY + id;
        Double member = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (member==null){
            //未点赞，数据库点赞＋1，保存点赞结果到redis
            boolean update = update().setSql("liked=liked+1").eq("id", id).update();
            if (update){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            //已点赞，点赞数量-1
            boolean update = update().setSql("liked=liked-1").eq("id", id).update();
            if (update){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result likesBlog(Long id) {
        //查询redis点赞用户前五名
        String key = BLOG_LIKED_KEY + id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5==null || top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }

        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> userDTO = userService.query().in("id",ids).orderByDesc("id").list()
        .stream().map(user ->
                BeanUtil.copyProperties(user, UserDTO.class)
        ).collect(Collectors.toList());

        return Result.ok(userDTO);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
